Scanning to discover a frequency

WRPI448
Posts: 11
Joined: Sat Feb 19, 2022 1:16 am

Scanning to discover a frequency

Post by WRPI448 » Wed Feb 23, 2022 11:30 pm

Seems like such a simple thing that has me stumped. Is there a way to scan VHF frequencies for an unknown channel? I want to add my buddies frequency to my 9600 for his landscaping company, but he doesn’t know what it is, as the radios are rentals. Anything?
Thank you ahead of time all! The OPENGD firmware is SO much nicer then factory!

WRPI448
Posts: 11
Joined: Sat Feb 19, 2022 1:16 am

Re: Scanning to discover a frequency

Post by WRPI448 » Wed Feb 23, 2022 11:59 pm

Okay, figured out that if you hold the up key in VFO mode it scans. But only a small range. How do you change that range?

G4EML
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Joined: Sat Nov 16, 2019 10:01 am

Re: Scanning to discover a frequency

Post by G4EML » Thu Feb 24, 2022 12:09 am

When you start the scan you can enter the lower and upper frequency limits.

See the manual at

https://github.com/LibreDMR/OpenGD77_Us ... o-scanning

Colin G4EML

WRPI448
Posts: 11
Joined: Sat Feb 19, 2022 1:16 am

Re: Scanning to discover a frequency

Post by WRPI448 » Thu Feb 24, 2022 1:13 am

BAD INFO.. Still learning
Last edited by WRPI448 on Thu Feb 24, 2022 3:51 pm, edited 2 times in total.

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F1RMB
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Location: Grenoble, France

Re: Scanning to discover a frequency

Post by F1RMB » Thu Feb 24, 2022 4:14 am

WRPI448 wrote:
Thu Feb 24, 2022 1:13 am
...
With radio off, hold blue button and turn on
...
No, this resets the settings, you do NOT want to do that.

Better off reading the user guide, it's detailed there:
https://github.com/LibreDMR/OpenGD77_Us ... o-scanning


Cheers.
---
Daniel

WRPI448
Posts: 11
Joined: Sat Feb 19, 2022 1:16 am

Re: Scanning to discover a frequency

Post by WRPI448 » Thu Feb 24, 2022 3:55 pm

Thank you for the reply. I searched the manual. Maybe I'm using the wrong terms.
Simplified..
The red button switches between channel mode and VFO mode.
It appears holding blue key and star switches between FM and DMR

Trying to scan DMR now to understand that further. I am new to DMR
If I understand it AT ALL, it will scan the frequencies I input for a range. IF it picks up on activity, it will display the frequency and TG. From there I should be able to start narrowing in on a TS, of CC?

G4EML
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Joined: Sat Nov 16, 2019 10:01 am

Re: Scanning to discover a frequency

Post by G4EML » Thu Feb 24, 2022 6:42 pm

If you are trying to find a completely unknown DMR signal it would be better to scan in FM mode until you find the signal. That will scan faster and will tell you the frequency. Set the channel step size to 12.5KHz to speed up the scanning.

(If you are trying to find the frequency of another radio in the same room, first remove the antenna from the GD77 to reduce the received signal strength. That will help prevent false responses.)

Once you know the frequency you can then stop the scan and press and hold SK2 to find the CC and TG.

WRPI448
Posts: 11
Joined: Sat Feb 19, 2022 1:16 am

Re: Scanning to discover a frequency

Post by WRPI448 » Thu Feb 24, 2022 7:02 pm

I'm learning more and more, day by day. Thank you.
So, if I scan in analogue FM, it will still pick up a DMR transmission, I just won't hear audio, correct?
Then Id switch to DMR, input that frequency, and scan again, this time its scanning for CC and TG, TS.

I tried this, but when it picks up a frequency in DMR mode, and I hit the blue SK, its doesn't latch or display any additional info.

Again, appreciate everyones help

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F1RMB
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Location: Grenoble, France

Re: Scanning to discover a frequency

Post by F1RMB » Thu Feb 24, 2022 7:07 pm

Hi,

In VFO, you just need to switch to DMR (SK2 + Star).
Pressing and holding the SK2 button, the software will try to find the CC, TS, TG, etc...

A nice website with tons of signal sounds, here DMR:
https://www.sigidwiki.com/wiki/Digital_ ... adio_(DMR)


Cheers.
---
Daniel

WRPI448
Posts: 11
Joined: Sat Feb 19, 2022 1:16 am

Re: Scanning to discover a frequency

Post by WRPI448 » Thu Feb 24, 2022 7:19 pm

I'm asking questions to try and further learn...
So, If I am on a frequency, with filters all off, my HT should pick up audio, regardless of the CC or TS, correct? I believe all this to be correct, as TS and C1 are inversed colors on the screen
Holding SK2 is essentially a "monitor" correct? When I hear activity on DMR, I hit the blue SK button and it just goes to static. While I am receiving I can see the CC and TS on the screen it appears

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